1. Field of the Invention
The invention relates to a new class of α-cyanoacrylate monomers which are useful as adhesives or sealants, and more particularly to compounds which are alkyl ester α-cyanoacrylate monomers. This invention further relates to the use of such alkyl ester α-cyanoacrylates monomers in α-cyanoacrylate compositions that are useful as tissue adhesives/sealants in surgical, medical and industrial applications, and to the production thereof.
2. State of the Art
Monomer and polymer adhesives/sealants are used in both industrial (including household) and medical/surgical applications. Included among these adhesives or sealants are the α-cyanoacrylates monomers and polymers resulting therefrom. Since the discovery of the adhesive/sealant properties of such monomers and polymers, they have found wide use due to the speed with which they cure, the strength of the resulting bond formed, and their relative ease of use. These characteristics have made α-cyanoacrylate compositions the primary choice for numerous adhesive applications such as bonding plastics, rubbers, glass, metals, wood, and, more recently, medical, biological or living tissues.
Medical and surgical applications of α-cyanoacrylate compositions include their use as alternates or adjuncts to surgical sutures, meshes and staples or other medical devices in wound closure, as well as for covering and protecting surface wounds such as lacerations, abrasions, burns, stomatitis, sores, and other surface wounds. When an α-cyanoacrylate composition is applied, it is usually applied in its monomeric form, and the resultant polymerization gives rise to the desired adhesive bond or sealant strength.
For example, polymerizable α-cyanoacrylate monomers and compositions comprising such monomers are disclosed in U.S. Pat. No. 5,328,687 to Leung et al. Suitable methods for applying such compositions to substrates, and particularly in medical applications, are described in, for example, U.S. Pat. Nos. 6,620,846 B1, 6,512,023B1, and 3,995,641, the contents each of which is incorporated by reference herein in its entirety.
U.S. Pat. No. 5,928,611 to Leung broadly discloses α-cyanoacrylate monomers having a large number of possible substituent groups. The disclosure focuses on α-cyanoacrylate monomers, with alternative representation of ester cyanoacrylate monomers having an organic radical substituent. However, the disclosure does not specify particular properties, such as absorbability, possessed by polymers formed with particular cyanoacrylate monomers.
U.S. Pat. No. 3,995,641 to Kronenthal et al. discloses carbalkoxyalkyl α-cyanoacrylate monomers that form absorbable polymer adhesives in mammalian tissue. Under some circumstances, absorbable polymer adhesives/sealants have benefits over non-absorbable polymer adhesives/sealants, particularly for some medical applications. However, some α-cyanoacrylate monomers have particularly slow reaction kinetics which reduce their practical value as surgical adhesives/sealants.
Therefore, there is still a need for α-cyanoacrylate compositions that exhibit a rapid cure rate sufficient for medical applications and produce an absorbable polymer adhesive/sealant. It is also desirable to have a monomer based internal adhesive or sealant composition that is capable of polymerizing in vivo to form an internal adhesive or sealant, in order to provide an opportunity for manipulation and re-alignment. Specifically, it is desirable that the adhesive or sealant composition fill internal cavities and voids, penetrating and conforming to the interstices and pores of the tissue, prior to curing or setting.
Additionally, it is desirable to have a monomer based internal adhesive or sealant composition that polymerizes in vivo, where the monomer, the composition thereof, and the resultant polymer are biocompatible. The resultant polymer should also be biodegradable.
Finally, it is desirable that the degradation products of the resultant polymer be both biocompatible and water soluble, so that the degradation products are completely eliminated from the human body as waste products.